The screen door is held locked in by a 3 pin locking mechanism which is embedded into the aluminium frame of the internal door and that 3 point locking is activated when you turn your door handle upwards to release the fly-wire outer door.

So not sure what model/year BT door you have.
The same principle as home security doors with triple locking mechanism.

Maybe you can drop a picture on this site so it can assessed further.

Regards,
Dave_________________Davo:
Life can be hard………...but a BT makes it all fun!

Most van accessory shops should have the clips, they are in the camec catalogue, you can order on line or over phone, and they will post. Should be available in Adelaide for sure.. I bought mine from my local van/camping accessory shop._________________The Wandering Rosiebears...
20ft, 10/2005, rooftop Oyster sat, OzGlide hitch
towed by; Iveco 50C18.
0417 007298